Selectively invert ICMP operands for better address optimization

tests_lit/llvm2ice_tests/address-mode-opt.ll

Index: tests_lit/llvm2ice_tests/address-mode-opt.ll
diff --git a/tests_lit/llvm2ice_tests/address-mode-opt.ll b/tests_lit/llvm2ice_tests/address-mode-opt.ll
index ccd301c4e8789d780060af78194f09db5fe0fd21..901d1f00723b366312acd50cda10a7d0640a6330 100644
--- a/tests_lit/llvm2ice_tests/address-mode-opt.ll
+++ b/tests_lit/llvm2ice_tests/address-mode-opt.ll
@@ -187,3 +187,20 @@ entry:
 ; CHECK: or
 ; CHECK-NOT: movss xmm{{[0-9]+}},DWORD PTR [{{e..}}*4+0xFFFF]
 }
+
+define internal void @invert_icmp(i32* %arg1, i32* %arg2) {
+entry:
+  %addr.other = load i32, i32* %arg2, align 1
+  br label %foo
+foo:

[Jim Stichnoth, 2016/07/08 11:45:46]

I would name this something like "next" instead of "foo", just to make it read a
bit more serious.

+  %addr.load = load i32, i32* %arg1, align 1
+  %cond = icmp slt i32 %addr.load, %addr.other
+  br i1 %cond, label %if.then, label %if.else
+if.then:
+  ret void
+if.else:
+  ret void
+; CHECK-LABEL: invert_icmp
+; CHECK: cmp {{e..}},DWORD PTR [{{e..}}]
+; CHECK: jle
+}